Power = Work/Time. Work has dimensions [ML²T⁻²], dividing by time [T] gives [ML²T⁻³]. Energy is [ML²T⁻²], force is [MLT⁻²], momentum is [MLT⁻¹]. This dimensional formula uniquely identifies power. Memory tip: Power = energy per second ⇒ dimensions include extra T⁻¹ factor. Frequently tested in dimensional analysis sections of competitive exams.
Explanation:
Using v² = u² - 2gH, at maximum height v = 0. So 0 = 20² - 2×10×H => 400 = 20H => H = 20 m. Alternative formula: H = u²/(2g) = 400/20 = 20 m. Remember to use consistent units. For quick calculation, u²/(2g) is handy.
Explanation:
Impulse = Force × time = change in momentum. Momentum = mass × velocity, dimensions [M][LT⁻¹] = [MLT⁻¹]. Force dimensions [MLT⁻²], multiplied by time gives [MLT⁻¹]. Same as momentum.
Explanation:
Recoil is due to action-reaction pair: gun exerts forward force on bullet, bullet exerts backward force on gun. Newton's third law states for every action there is equal and opposite reaction. Conservation of momentum also explains recoil, but the immediate law is third law. Gun recoil velocity is calculated using conservation of momentum derived from third law.
No comments yet. Be the first to start the discussion!